The primary thrust of this grant proposal is to pursue findings obtained in earlier work and in preliminary investigations which indicate that intravenous alcohol self-administration can be modified by drug pretreatment, might be modified by physical dependence development, but might not be altered by tolerance development. In three separate studies, rhesus monkeys with chronically implanted venous catheters will receive intravenous infusions of alcohol, contingent on lever responses and according to schedules of reinforcement. Variables of access time and non-contingent infusions of alcohol and other drugs will be appropriately manipulated and effects observed on rates and patterns of both alcohol and food-reinforced responding in order to determine the effect of intoxication, tolerance, and dependence on the reinforcing property of alcohol.